Yup, more idle problems

dz01 · Jun 29, 2018

My 93 LX has been running great for about 2 years now after I ran through the Surging Idle Checklist and fixed about 8 issues.

Now all the sudden, I'm seeing some odd idle behavior, but different than what I had before. Here are the details:

- Car runs great for 15 minutes or so then the idle climbs to 2,000 rpm and basically stays there at idle. While I'm driving it feels like the cruise control is on since the idle is kept high. And shifting sucks since the RPMs just hang

- I can shut car off, turn it right back on and it runs fine again for a while, but eventually will idle again at 2K

- I have no codes showing

I figured I'd throw a post out to see if anyone else experienced this issue. I can run through the Surging Idle Checklist again, but this seems different in that the car runs great one minute, then not the next.

RangerJoe · Jun 29, 2018

IAC or vacuum leak are first that come to mind.

Joe

jrichker · Jun 29, 2018

RangerJoe said:
IAC or vacuum leak are first that come to mind.

Joe

dz01 said:
My 93 LX has been running great for about 2 years now after I ran through the Surging Idle Checklist and fixed about 8 issues.

Now all the sudden, I'm seeing some odd idle behavior, but different than what I had before. Here are the details:

- Car runs great for 15 minutes or so then the idle climbs to 2,000 rpm and basically stays there at idle. While I'm driving it feels like the cruise control is on since the idle is kept high. And shifting sucks since the RPMs just hang

- I can shut car off, turn it right back on and it runs fine again for a while, but eventually will idle again at 2K

- I have no codes showing

I figured I'd throw a post out to see if anyone else experienced this issue. I can run through the Surging Idle Checklist again, but this seems different in that the car runs great one minute, then not the next.

You have TPS problem - the TPS output affects idle speed and spark advance.

TPS Troubleshooting and testing

Revised 29-Jun-2018 to add increasing idle speed after engine start.

The TPS signal ground is not the same as the engine block or car body ground. Do not use the engine block or car body as a ground when checking the signal ground wiring or the TPS voltage!!! You will get incorrect readings that will vary with the amount of electrical load on the electrical system.

Setting the TPS: you'll need a good Digital Voltmeter (DVM) to do the job. Set the TPS voltage at .5- 1.1 range. Because of the variables involved with the tolerances of both computer and DVM, I would shoot for somewhere between .6 and 1.0 volts. Unless you have a Fluke or other high grade DVM, the second digit past the decimal point on cheap DVM’s is probably fantasy. There is no advantage to setting it to .99; that is a BOZO Internet myth, complete with red nose and big floppy shoes.

Since the computer zeros out the TPS voltage every time it powers up, playing with the settings isn't an effective aid to performance or drivability. The main purpose of checking the TPS is to make sure it isn't way out of range and causing problems.

Wire colors & functions:
Orange/white = 5 volt VREF from the computer
Dark Green/lt green = TPS output to computer
Black/white = Signal ground from computer

TPS troubleshooting steps:
1.) Use the Orange/white & Black white wires to verify the TPS has the correct 5 volts source from the computer.
2.) Use the Dark Green/lt green & Black/white wires to set the TPS base voltage. Try this... All you need is less than 1.0 volt at idle and more than 4.25 at Wide Open Throttle (WOT). You'll need a voltmeter with a 1 or 3 volt low scale to do the job.

The Orange/White wire is the VREF 5 volts from the computer. You use the Dark Green/Lt green wire (TPS signal) and the Black/White wire (TPS ground) to set the TPS. Use a pair of safety pins to probe the TPS connector from the rear of the connector. You may find it a little difficult to make a good connection, but keep trying. Put the safety pins in the Dark Green/Lt green wire and Black/White wire. Make sure the ignition switch is in the Run position but the engine isn't running. Set the voltmeter on the 2 volt range if it doesn’t auto range.

Here’s a TPS tip I got from NoGo50

When you installed the sensor make sure you place it on the peg right and then tighten it down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the front screw enough so you can move it just a little in very small increments. I wouldn’t try to adjust it using marks.

(copied from MustangMax, Glendale AZ)

A.) Always adjust the TPS and Idle with the engine at operating temp. Dive it around for a bit if you can and get it nice and warm.

B.) When you probe the leads of the TPS, do not use an engine ground, put the ground probe into the lead of the TPS. You should be connecting both meter probes to the TPS and not one to the TPS and the other to ground.

C.) Always reset the computer whenever you adjust the TPS or clean/change any sensors. I just pull the battery lead for 10 minutes.

D.) The key is to adjust the TPS voltage and reset the computer whenever the idle screw is changed.

TPS voltage should be less than 1.1 volt at closed throttle and 4.25 volts or more at WOT

The TPS is a variable resistor, must like the volume control knob on a cheap radio. We have all heard them crackle and pop when the volume is adjusted. The TPS sensor has the same problem: wear on the resistor element makes places that create electrical noise. This electrical noise confuses the computer, because it expects to see a smooth increase or decrease as the throttle is opened or closed.

TPS testing: most of the time a failed TPS will set code 23 or 63, but not always. Use either an analog meter or a DVM with an analog bar graph and connect the leads as instructed above. Turn the ignition switch to the Run position, but do not start the engine. Note the voltage with the throttle closed. Slowly open the throttle and watch the voltage increase smoothly, slowly close the throttle and watch the voltage decrease smoothly. If the voltage jumps around and isn’t smooth, the TPS has some worn places in the resistor element. When the throttle is closed, make sure that the voltage is the same as what it was when you started. If it varies more than 10%, the TPS is suspect of being worn in the idle range of its travel.

TPS will not go below 1 volt

Note: Make all resistance checks with the ignition switch in the OFF position. Failure to do so will result in incorrect results and may possibly damage the meter.

Engine mounted sensor circuit: Check the resistance between the black/white wire on the TPS and battery ground. It should be less than 1 ohm. Higher resistance than 1 ohm indicates a problem with the 10 pin connector, computer or the splice inside the main harness where the wire from the 10 pin connectors joins the rest of the black/white wire.

See the graphic for the location of the 10 pin connectors:
Diagram courtesy of Tmoss & Stang&2birds

See the graphic for the 10 pin connector circuit layout.

Unplug the white 10 pin connector to do some resistance testing. It is good time to clean the connector pins and examine the connector for corrosion, broken wire or other damage. See http://www.themustangstop.com/tech-articles/cleaning-10-pin-connectors-mustang for help in this department.

If the resistance on the TPS Black/White wire and pin 1 of the white engine fuel injector harness 10 pin connector is more than 1.0 ohm, you have bad connection or broken wiring. Repeat the test using the pin 1 of the white body side 10 pin connector and battery ground. You should have less that 1 ohm. More than that is a damaged signal ground inside the computer or bad connections or wiring.[/b]

Idle speed increases after the engine has started and been driven:
When you start the car, the computer reads the TPS output voltage and uses that as a starting baseline or minimum TPS voltage for the TPS sensor.

As the engine warms up, the TPS voltage can slowly creep up past whatever voltage it saw when the engine first started. That causes the idle RPM to increase.

When you shut the ignition off and then restart the engine, the computer reads the voltage and sets whatever voltage it sees as the minimum TPS voltage for the TPS sensor, even if that voltage is more than 1.1 volt.

The first place to look is for a bad TPS signal ground, broken signal ground wire, or bad connection in the TPS wiring. The TPS connector plug and the 10 pin connector are the two most likely culprits.

The other thing to consider is a bad TPS sensor. Again, dumping the computer codes is a must do item on your troubleshooting checklist. See http://www.stangnet.com/mustang-forums/threads/how-to-pull-codes-from-eec4.889006/ or "Surging Idle Checklist

dz01 · Jul 2, 2018

jrichker said:
You have TPS problem - the TPS output affects idle speed and spark advance.

TPS Troubleshooting and testing

Revised 29-Jun-2018 to add increasing idle speed after engine start.

The TPS signal ground is not the same as the engine block or car body ground. Do not use the engine block or car body as a ground when checking the signal ground wiring or the TPS voltage!!! You will get incorrect readings that will vary with the amount of electrical load on the electrical system.

Setting the TPS: you'll need a good Digital Voltmeter (DVM) to do the job. Set the TPS voltage at .5- 1.1 range. Because of the variables involved with the tolerances of both computer and DVM, I would shoot for somewhere between .6 and 1.0 volts. Unless you have a Fluke or other high grade DVM, the second digit past the decimal point on cheap DVM’s is probably fantasy. There is no advantage to setting it to .99; that is a BOZO Internet myth, complete with red nose and big floppy shoes.

Since the computer zeros out the TPS voltage every time it powers up, playing with the settings isn't an effective aid to performance or drivability. The main purpose of checking the TPS is to make sure it isn't way out of range and causing problems.

Wire colors & functions:
Orange/white = 5 volt VREF from the computer
Dark Green/lt green = TPS output to computer
Black/white = Signal ground from computer

TPS troubleshooting steps:
1.) Use the Orange/white & Black white wires to verify the TPS has the correct 5 volts source from the computer.
2.) Use the Dark Green/lt green & Black/white wires to set the TPS base voltage. Try this... All you need is less than 1.0 volt at idle and more than 4.25 at Wide Open Throttle (WOT). You'll need a voltmeter with a 1 or 3 volt low scale to do the job.

The Orange/White wire is the VREF 5 volts from the computer. You use the Dark Green/Lt green wire (TPS signal) and the Black/White wire (TPS ground) to set the TPS. Use a pair of safety pins to probe the TPS connector from the rear of the connector. You may find it a little difficult to make a good connection, but keep trying. Put the safety pins in the Dark Green/Lt green wire and Black/White wire. Make sure the ignition switch is in the Run position but the engine isn't running. Set the voltmeter on the 2 volt range if it doesn’t auto range.

Here’s a TPS tip I got from NoGo50

When you installed the sensor make sure you place it on the peg right and then tighten it down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the front screw enough so you can move it just a little in very small increments. I wouldn’t try to adjust it using marks.

(copied from MustangMax, Glendale AZ)

A.) Always adjust the TPS and Idle with the engine at operating temp. Dive it around for a bit if you can and get it nice and warm.

B.) When you probe the leads of the TPS, do not use an engine ground, put the ground probe into the lead of the TPS. You should be connecting both meter probes to the TPS and not one to the TPS and the other to ground.

C.) Always reset the computer whenever you adjust the TPS or clean/change any sensors. I just pull the battery lead for 10 minutes.

D.) The key is to adjust the TPS voltage and reset the computer whenever the idle screw is changed.

TPS voltage should be less than 1.1 volt at closed throttle and 4.25 volts or more at WOT

The TPS is a variable resistor, must like the volume control knob on a cheap radio. We have all heard them crackle and pop when the volume is adjusted. The TPS sensor has the same problem: wear on the resistor element makes places that create electrical noise. This electrical noise confuses the computer, because it expects to see a smooth increase or decrease as the throttle is opened or closed.

TPS testing: most of the time a failed TPS will set code 23 or 63, but not always. Use either an analog meter or a DVM with an analog bar graph and connect the leads as instructed above. Turn the ignition switch to the Run position, but do not start the engine. Note the voltage with the throttle closed. Slowly open the throttle and watch the voltage increase smoothly, slowly close the throttle and watch the voltage decrease smoothly. If the voltage jumps around and isn’t smooth, the TPS has some worn places in the resistor element. When the throttle is closed, make sure that the voltage is the same as what it was when you started. If it varies more than 10%, the TPS is suspect of being worn in the idle range of its travel.

TPS will not go below 1 volt

Note: Make all resistance checks with the ignition switch in the OFF position. Failure to do so will result in incorrect results and may possibly damage the meter.

Engine mounted sensor circuit: Check the resistance between the black/white wire on the TPS and battery ground. It should be less than 1 ohm. Higher resistance than 1 ohm indicates a problem with the 10 pin connector, computer or the splice inside the main harness where the wire from the 10 pin connectors joins the rest of the black/white wire.

See the graphic for the location of the 10 pin connectors:
Diagram courtesy of Tmoss & Stang&2birds

See the graphic for the 10 pin connector circuit layout.

Unplug the white 10 pin connector to do some resistance testing. It is good time to clean the connector pins and examine the connector for corrosion, broken wire or other damage. See http://www.themustangstop.com/tech-articles/cleaning-10-pin-connectors-mustang for help in this department.

If the resistance on the TPS Black/White wire and pin 1 of the white engine fuel injector harness 10 pin connector is more than 1.0 ohm, you have bad connection or broken wiring. Repeat the test using the pin 1 of the white body side 10 pin connector and battery ground. You should have less that 1 ohm. More than that is a damaged signal ground inside the computer or bad connections or wiring.[/b]

Idle speed increases after the engine has started and been driven:
When you start the car, the computer reads the TPS output voltage and uses that as a starting baseline or minimum TPS voltage for the TPS sensor.

As the engine warms up, the TPS voltage can slowly creep up past whatever voltage it saw when the engine first started. That causes the idle RPM to increase.

When you shut the ignition off and then restart the engine, the computer reads the voltage and sets whatever voltage it sees as the minimum TPS voltage for the TPS sensor, even if that voltage is more than 1.1 volt.

The first place to look is for a bad TPS signal ground, broken signal ground wire, or bad connection in the TPS wiring. The TPS connector plug and the 10 pin connector are the two most likely culprits.

The other thing to consider is a bad TPS sensor. Again, dumping the computer codes is a must do item on your troubleshooting checklist. See http://www.stangnet.com/mustang-forums/threads/how-to-pull-codes-from-eec4.889006/ or "Surging Idle Checklist

dz01 · Jul 2, 2018

Thanks guys! I’ll try that this weekend.

Boostedpimp · Jul 3, 2018

I've had that before and got away with cleaning the iac out to resolve it

dz01 · Jul 5, 2018

jrichker said:
You have TPS problem - the TPS output affects idle speed and spark advance.

TPS Troubleshooting and testing

Revised 29-Jun-2018 to add increasing idle speed after engine start.

The TPS signal ground is not the same as the engine block or car body ground. Do not use the engine block or car body as a ground when checking the signal ground wiring or the TPS voltage!!! You will get incorrect readings that will vary with the amount of electrical load on the electrical system.

Setting the TPS: you'll need a good Digital Voltmeter (DVM) to do the job. Set the TPS voltage at .5- 1.1 range. Because of the variables involved with the tolerances of both computer and DVM, I would shoot for somewhere between .6 and 1.0 volts. Unless you have a Fluke or other high grade DVM, the second digit past the decimal point on cheap DVM’s is probably fantasy. There is no advantage to setting it to .99; that is a BOZO Internet myth, complete with red nose and big floppy shoes.

Since the computer zeros out the TPS voltage every time it powers up, playing with the settings isn't an effective aid to performance or drivability. The main purpose of checking the TPS is to make sure it isn't way out of range and causing problems.

Wire colors & functions:
Orange/white = 5 volt VREF from the computer
Dark Green/lt green = TPS output to computer
Black/white = Signal ground from computer

TPS troubleshooting steps:
1.) Use the Orange/white & Black white wires to verify the TPS has the correct 5 volts source from the computer.
2.) Use the Dark Green/lt green & Black/white wires to set the TPS base voltage. Try this... All you need is less than 1.0 volt at idle and more than 4.25 at Wide Open Throttle (WOT). You'll need a voltmeter with a 1 or 3 volt low scale to do the job.

The Orange/White wire is the VREF 5 volts from the computer. You use the Dark Green/Lt green wire (TPS signal) and the Black/White wire (TPS ground) to set the TPS. Use a pair of safety pins to probe the TPS connector from the rear of the connector. You may find it a little difficult to make a good connection, but keep trying. Put the safety pins in the Dark Green/Lt green wire and Black/White wire. Make sure the ignition switch is in the Run position but the engine isn't running. Set the voltmeter on the 2 volt range if it doesn’t auto range.

Here’s a TPS tip I got from NoGo50

When you installed the sensor make sure you place it on the peg right and then tighten it down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the front screw enough so you can move it just a little in very small increments. I wouldn’t try to adjust it using marks.

(copied from MustangMax, Glendale AZ)

A.) Always adjust the TPS and Idle with the engine at operating temp. Dive it around for a bit if you can and get it nice and warm.

B.) When you probe the leads of the TPS, do not use an engine ground, put the ground probe into the lead of the TPS. You should be connecting both meter probes to the TPS and not one to the TPS and the other to ground.

C.) Always reset the computer whenever you adjust the TPS or clean/change any sensors. I just pull the battery lead for 10 minutes.

D.) The key is to adjust the TPS voltage and reset the computer whenever the idle screw is changed.

TPS voltage should be less than 1.1 volt at closed throttle and 4.25 volts or more at WOT

The TPS is a variable resistor, must like the volume control knob on a cheap radio. We have all heard them crackle and pop when the volume is adjusted. The TPS sensor has the same problem: wear on the resistor element makes places that create electrical noise. This electrical noise confuses the computer, because it expects to see a smooth increase or decrease as the throttle is opened or closed.

TPS testing: most of the time a failed TPS will set code 23 or 63, but not always. Use either an analog meter or a DVM with an analog bar graph and connect the leads as instructed above. Turn the ignition switch to the Run position, but do not start the engine. Note the voltage with the throttle closed. Slowly open the throttle and watch the voltage increase smoothly, slowly close the throttle and watch the voltage decrease smoothly. If the voltage jumps around and isn’t smooth, the TPS has some worn places in the resistor element. When the throttle is closed, make sure that the voltage is the same as what it was when you started. If it varies more than 10%, the TPS is suspect of being worn in the idle range of its travel.

TPS will not go below 1 volt

Note: Make all resistance checks with the ignition switch in the OFF position. Failure to do so will result in incorrect results and may possibly damage the meter.

Engine mounted sensor circuit: Check the resistance between the black/white wire on the TPS and battery ground. It should be less than 1 ohm. Higher resistance than 1 ohm indicates a problem with the 10 pin connector, computer or the splice inside the main harness where the wire from the 10 pin connectors joins the rest of the black/white wire.

See the graphic for the location of the 10 pin connectors:
Diagram courtesy of Tmoss & Stang&2birds

See the graphic for the 10 pin connector circuit layout.

Unplug the white 10 pin connector to do some resistance testing. It is good time to clean the connector pins and examine the connector for corrosion, broken wire or other damage. See http://www.themustangstop.com/tech-articles/cleaning-10-pin-connectors-mustang for help in this department.

If the resistance on the TPS Black/White wire and pin 1 of the white engine fuel injector harness 10 pin connector is more than 1.0 ohm, you have bad connection or broken wiring. Repeat the test using the pin 1 of the white body side 10 pin connector and battery ground. You should have less that 1 ohm. More than that is a damaged signal ground inside the computer or bad connections or wiring.[/b]

Idle speed increases after the engine has started and been driven:
When you start the car, the computer reads the TPS output voltage and uses that as a starting baseline or minimum TPS voltage for the TPS sensor.

As the engine warms up, the TPS voltage can slowly creep up past whatever voltage it saw when the engine first started. That causes the idle RPM to increase.

When you shut the ignition off and then restart the engine, the computer reads the voltage and sets whatever voltage it sees as the minimum TPS voltage for the TPS sensor, even if that voltage is more than 1.1 volt.

The first place to look is for a bad TPS signal ground, broken signal ground wire, or bad connection in the TPS wiring. The TPS connector plug and the 10 pin connector are the two most likely culprits.

The other thing to consider is a bad TPS sensor. Again, dumping the computer codes is a must do item on your troubleshooting checklist. See http://www.stangnet.com/mustang-forums/threads/how-to-pull-codes-from-eec4.889006/ or "Surging Idle Checklist

Checked my TPS- .92 when grounding to TB bolt and .84 when grounding to the black wire on the TPS. Both seem well within range, but I backed it down a bit- more like .84 and .78 respectively. I've heard (even though below 1.0 is the goal) that some have had good luck with the 1.2 range. I figure I'll go lower first and see if any difference, then go higher. If not difference, I'll return to original setting and go after the salt and pepper shakers. Both my TPS and IAC are a few years old, but probably only have 500 miles on both.

jrichker · Jul 6, 2018

dz01 said:
Checked my TPS- .92 when grounding to TB bolt and .84 when grounding to the black wire on the TPS. Both seem well within range, but I backed it down a bit- more like .84 and .78 respectively. I've heard (even though below 1.0 is the goal) that some have had good luck with the 1.2 range. I figure I'll go lower first and see if any difference, then go higher. If not difference, I'll return to original setting and go after the salt and pepper shakers. Both my TPS and IAC are a few years old, but probably only have 500 miles on both.

Your reply indicates that either you didn't read the tech tip very well or you didn't understand it completely.

You comments indicate that there is some misunderstanding of some very important principles about the TPS. The two areas are: what to use for a ground and setting the TPS to any specific voltage. Go back, read slowly and digest what was written.

dz01 · Jul 6, 2018

jrichker said:
Your reply indicates that either you didn't read the tech tip very well or you didn't understand it completely.

You comments indicate that there is some misunderstanding of some very important principles about the TPS. The two areas are: what to use for a ground and setting the TPS to any specific voltage. Go back, read slowly and digest what was written.

Funny thing about the interwebs; a wealth of information, however, much of which is contradictory. For example, about half of the info I got on this topic was to ground on the body (LMR was actually one of them) and the other half to ground on the connector. Figured I'd do both since it only took me an extra few seconds and compare the two.

Also about a 50/50 split was the adjustment- one camp said just get between .6-1.0 and the other actually noticed a difference whether on the low or high end of that range (one guy actually claimed he gained 25 HP!). Figured I'd move to the low end, then the high end and compare. If I see no difference, I have 2 other TPSs I can try. If no difference in those, I'll reinstall the original one, adjust within the range and move on to the salt/pepper shakers.

The web is great to give ideas and suggestions to troubleshoot, but I tend to find unless I'm doing/seeing it myself, I can't rule it out. I'm sure adjusting the TPS won't make a difference, but I'm going to try anyway. After all, I had someone on the board convinced the TAB and TAD cannot affect idle and I proved that wrong despite avoiding any troubleshooting in that area for months. My car ran perfectly for a few years once I switched the backwards vacuum lines.

I'll report back soon (which I'm sure will track with the guidance provided initially).

Mustang5L5 · Jul 6, 2018

If you actually read the ECU programming, the min value for the TPS is 0.5 volts and the max is 1.25 volts. There's a few different ranges given on the internet but the actual programming is anything less than 0.5 generates code 23 and anything more than 1.25 generates code 63. Anything in there is acceptable although many target 1.0v or so which is fine but not necessary.

Another value to check is WOT voltage. Sweep open your throttle and record the voltage. Now let it close and subtract the idle voltage from WOT voltage. You want 3.13+ volts difference.

You should test to sensor ground when testing any sort of sensor. Most often body ground is at same potential as sensor grounds but of there is ever a ground issue you'll find the readings might be different. Youbwant to use the same "clean" ground the ECU is also using.

THe TPS is often given way too much credit for what it does. If it don't haveva code 23/63 for it (min and max idle voltage) and you verify your sweep range is greater than 3.1 volts, move on to the next.

RangerJoe · Jul 6, 2018

I will add this. I had burned up pin 46 in my ECU, which provides a ground for a lot of the sensors. When I was trouble shooting this, before I knew what it was, I was testing the TPS. Using the tps ground got me readings outside of the accepted range. Using the body as a ground worked out better. I don't think it registered with me at the time, but that should have been an immediate clue as to what was going on. All that said just to reiterate what has been said....use the sensor ground for testing.

Joe

dz01 · Jul 9, 2018

Thanks for all the info!

I didn't have a lot of time this weekend, but I was able to check volts on WOT.

So I had about .84 when grounding to the TPS initially which was the same when I tested again yesterday. My WOT test yielded ~13.35 on 3 separate tests. Each time the volts when back down to idle, the number increased slightly.

- First WOT test when from ~13.35 down to .87
- Second WOT test when from ~13.35 down to .91
- Third WOT test when from ~13.35 down to .93

Assuming I did this test correctly, my WOT test is definitely over the 4.25 volts so that shoudl be fine.
Also odd for my idle volts to climb each time I tested WOT but the test above states "When the throttle is closed, make sure that the voltage is the same as what it was when you started. If it varies more than 10%, the TPS is suspect of being worn in the idle range of its travel." If I did my math right, I'm seeing a 7-8% variation which could point to a worn TPS- sound right?

I put a BBK TPS in my car a few years ago. Seem to be mixed reviews on the BBK product vs. the stock TPS.

Mustang5L5 · Jul 9, 2018

13.3 volts? Is that a typo?

The sensor should be seeing a 5 volt reference, so that should be the highest value you can obtain. Are you really seeing 13 volts on the tps sensor?

dz01 · Jul 9, 2018

Mustang5L5 said:
13.3 volts? Is that a typo?

The sensor should be seeing a 5 volt reference, so that should be the highest value you can obtain. Are you really seeing 13 volts on the tps sensor?

Correct, although now I'm second guessing I had the meter on the right setting. Measured from the black and green wires, showed .84 at the initial test (so that should point to meter being set correctly otherwise I would assume that would be off), then WOT the number climbed to 13.xx.

Let me go back tonight and make sure meter is set correctly.

dz01 · Jul 9, 2018

Something must have been wrong with my meter. Wouldn't turn on so I had to borrow another one. Batteries might have been weak since digital display was not very bright.

Grounding new meter on black wire showed .97 and WOT was 4.8

Adjusted TPS counterclockwise to show .88 and WOT 4.72. Tested multiple times and came up with the same two numbers. I'm out of adjustment with current holes in TPS so I'd have to widen to get more adjustment.

WOT is over the 4.25.

So options:

- Run with new adjustment and see if any difference
- Widen TPS hole and see if I can get down to 4.25 or less at WOT
- Replace sensor

Thoughts?

jrichker · Jul 9, 2018

dz01 said:
Something must have been wrong with my meter. Wouldn't turn on so I had to borrow another one. Batteries might have been weak since digital display was not very bright.

Grounding new meter on black wire showed .97 and WOT was 4.8

Adjusted TPS counterclockwise to show .88 and WOT 4.72. Tested multiple times and came up with the same two numbers. I'm out of adjustment with current holes in TPS so I'd have to widen to get more adjustment.

WOT is over the 4.25.

So options:

- Run with new adjustment and see if any difference
- Widen TPS hole and see if I can get down to 4.25 or less at WOT
- Replace sensor

Thoughts?

@Mustang5L5 and I have told you the same thing.
Quit messing with the TPS settings; as long as they are in the range you measured, changing them does not do anything positive for performance. If you want to spend hours reading the GUFB manual, I'll email you a link or the actual PDF document.

dz01 · Jul 9, 2018

jrichker said:
@Mustang5L5 and I have told you the same thing.
Quit messing with the TPS settings; as long as they are in the range you measured, changing them does not do anything positive for performance. If you want to spend hours reading the GUFB manual, I'll email you a link or the actual PDF document.

Read the WOT wrong, needs to be 4.25 or over which I am. TPS appears good so on to the next.

Mstng93SSP · Jul 10, 2018

You sure you have no codes? When my engine coolant temp sensor went bad it caused a high idle, but I had a code (I think it was 51).

Mustang5L5 · Jul 10, 2018

dz01 said:
Adjusted TPS counterclockwise to show .88 and WOT 4.72. Tested multiple times and came up with the same two numbers. I'm out of adjustment with current holes in TPS so I'd have to widen to get more adjustment.

Those numbers are fine. Don't do a thing. Move onto the next.

dz01 · Jul 10, 2018

Mustang5L5 said:
Those numbers are fine. Don't do a thing. Move onto the next.

Thanks. 10-pin connector next

Yup, more idle problems

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That is…until I whipped out my Bissell

I leave the horn on while driving

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That is…until I whipped out my Bissell

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You have a nice rear end there Dave.

That is…until I whipped out my Bissell

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